<!DOCTYPE html>
<html>
	<head>
		<meta charset="utf-8">
		<title></title>
		<style type="text/css">
			.menu>li{
				display: inline-block;
				position: relative;
				padding: 0px 20px 0px 20px;
			}
			li>ol{
				display: none;
			}
			.menu>li:hover>ol{
				display: block;
				position: absolute;
				width: 100px;
				left: -20px;
			}
			li{
				list-style-type: none;
			}
		</style>
	</head>
	<body>
		<ol class="menu">
			<li>一级菜单
				<ol>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
				</ol>
			</li>
			<li>一级菜单
				<ol>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
				</ol>
			</li>
			<li>一级菜单 
				<ol>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
					<li>二级菜单</li>
				</ol>
			</li>
		</ol>
	</body>
</html>
